To migrate a single instance queue manager, to a multi-instance queue manager, on
Windows platforms, you must move the queue manager data
to a shared directory, and reconfigure the queue manager on two other servers.
Before you begin
You must check the prerequisites for running a multi-instance queue manager as part of this task.
For
a list of tested environments, see Testing
statement for IBM® MQ multi-instance queue manager file
systems.
Other
environments might work; a test tool is provided with IBM MQ to assist you in qualifying other environments.
You must have three servers to run a multi-instance queue manager. One server has a shared file
system to store the queue manager data and logs. The other servers run the active and standby
instances of the queue manager.
About this task
You have a single-instance queue manager that you want to convert to a multi-instance queue
manager. The queue manager conversion itself is straightforward, but you must do other tasks to
create a fully automated production environment.
You must check the prerequisites for a multi-instance queue manager, set up the environment and
check it. You must set up a monitoring and management system to detect if the multi-instance queue
manager has failed and been automatically restarted. You can then find out what caused the restart,
remedy it, and restart the standby. You must also modify applications, or the way applications are
connected to the queue manager, so that they can resume processing after a queue manager restart.
Procedure
-
Check the operating system that you are going to run the queue manager on, and the file system
on which the queue manager data and logs are stored on. Check that they can run a multi-instance
queue manager.
-
Consult Testing statement for IBM MQ
multi-instance queue manager file systems. See whether the combination of operating system and file
system is tested and capable of running a multi-instance queue manager.
A shared file system must provide lease-based locking to be adequate to run multi-instance
queue managers. Lease-based locking is a recent feature of some shared file systems, and in some
case fixes are required. The support statement provides you with the essential information.
-
Run amqmfsck to verify that the file system is configured correctly.
File systems are sometimes configured with performance at a premium over data integrity. It is
important to check the file system configuration. A negative report from the
amqmfsck tool tells you the settings are not adequate. A positive result is an
indication that the file system is adequate, but the result is not a definitive statement that the
file system is adequate. It is a good indication.
-
Run the integrity checking application provided in the technote, Testing a shared file system for compatibility with IBM MQ Multi-instance Queue Managers.
The checking application tests that the queue manager is restarting correctly.
-
Configure a user and group to be able to access a share on the networked file system from each
server that is running a queue manager instance.
-
Set up a directory for the share on the networked file system with the correct access
permissions.
For example, create a root directory on the share called
MQHA
that has
subdirectories
data and
logs. Each queue manager creates
its own data and log directories under
data and
logs.
Create
drive \MQHA
on the shared drive. The owner is a member of
mqm
.
mqm
must have full-control authority. Create a share for
drive\MQHA
.
If you are using an NFS v4 file server, add the
line /MQHA * rw,sync,no_wdelay,fsid=0)
to etc/exports, and
then start the NFS daemon: /etc/init.d/nfs start
.
-
Copy the queue manager data and the logs to the share.
You can choose to copy files manually, by following the procedure to back up the queue
manager. On Windows, you can run the
hamvmqm command to move the queue manager data to the share. The
hamvmqm command works for queue managers created before IBM WebSphere MQ 7.0.1, and not reconfigured with a datapath, or for queue
managers that do not have a DataPath configuration attribute. Choose one of
these methods:
-
Update the queue manager configuration information stored on the current queue manager
server.
- If you moved the queue manager data and logs by running the hamvmqm command,
the command has already modified the configuration information correctly for you.
- If you moved the queue manager data and logs manually, you must complete the following steps.
- Modify the log registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\IBM\WebSphere MQ\Installation\MQ_INSTALLATION_NAME\Configuration\QueueManager\QMgrName\Log
"LogPath"="share\\logs\\QMgrName\\"
- Modify the Prefix registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\IBM\WebSphere MQ\Installation\MQ_INSTALLATION_NAME\Configuration\QueueManager\QMgrName
"Prefix"="share\\data"
where QMgrName
is the representation of the queue manager
name in the existing registry key on Windows.
share
is share where the data and logs are moved to.
-
Add the queue manager configuration information to the new queue manager server.
-
Run the dspmqinf command to display the queue manager information
Run the command on the server that ran the queue
manager.
dspmqinf -o command QMgrName
The command output is formatted ready to create a queue manager configuration.
addmqinf -s QueueManager -v Name= QMgrName -v Directory=
QMgrName -v Prefix=d:\var\mqm Datapath= \share\data\QMgrName
-
Create a queue manager configuration on the other server.
Run the addmqinf command copied from the previous output.
-
Add the network address of the new server to the connection name in client and channel
definitions.
-
Find all the client, sender, and requester TCPIP settings that refer to the server.
- Client settings might be in Client Definition Tables (CCDT), in environment variables, in
Java properties files, or in client code.
- Cluster channels automatically discover the connection name of a queue manager from its cluster
receiver channel. As long as the cluster receiver channel name is blank or omitted, TCPIP discovers
the IP address of the server hosting the queue manager.
-
Modify the connection name for each of these connections to include the TCPIP addresses of both
servers that are hosting the multi-instance queue manager.
For example, change the following connection name:
echo DISPLAY CHANNEL(ENGLAND) CONNAME | runmqsc QM1
5724-H72 (C) Copyright IBM Corp. 1994, 2024. ALL RIGHTS RESERVED.
Starting MQSC for queue manager QM1.
1: DISPLAY CHANNEL(ENGLAND) CONNAME
AMQ8414: Display Channel details.
CHANNEL(ENGLAND) CHLTYPE(SDR)
CONNAME(LONDON)
into:
echo ALTER CHANNEL(ENGLAND) CHLTYPE(SDR) CONNAME('LONDON, BRISTOL') | runmqsc QM1
-
Update your monitoring and management procedures to detect the queue manager restarting.
-
Update client applications to be automatically reconnectable, if appropriate.
-
Update the start procedure for your IBM MQ
applications to be started as queue manager services.
-
Start each instance of the queue manager, permitting them to be highly available.
The first instance of the queue manager that is started becomes the active instance. Issue the
command twice, once on each server.
What to do next
To get the highest availability out of multi-instance queue managers, you must design client
applications to be reconnectable and server applications to be restartable; see Application recovery.